From: House Committee on Science, Space, and Technology
Posted: Saturday, May 10, 2003
Testimony to the House Subcommittee on Space and Aeronautics
On the Assessment of Apollo Hardware for CRV and CTV
By Dale Myers
A team (Appendix 1) was chartered by NASA to make a top-level assessment of the viability of using the Apollo Command and Service Modules (CSM) as the basis for a Crew Return Vehicle (CRV), and potentially for a Crew Transfer Vehicle (CTV) for the International Space Station (ISS). This assessment was conducted on March 13-14, 2003. None of the conclusions can be other than judgemental, due to the short time of study, but this small group does cover a broad background of knowledge and experience about Apollo and about human space flight.
The Team concluded unanimously that an Apollo-derived Crew Return Vehicle (CRV) concept, with a 4 to 6 person crew, appears to have the potential of meeting most of the OSP CRV Level 1 requirements. An Apollo derived Crew Transport Vehicle (CTV) would also appear to be able to meet most of the OSP CTV Level 1 requirements with the addition of a service module. The team also surmised that there would be an option to consider the Apollo CSM concept for a common CRV/CTV system.
It was further concluded that using the Apollo Command Module (CM) and Service Module (SM) as an ISS CRV and CTV has sufficient merit to warrant a serious detailed study of the performance, cost, and schedule for this approach, in comparison with other OSP approaches, to the same Level 1 requirements.
Cost and Schedule
It was not possible for the team to make an estimate of the cost of the design, development, manufacturing and operational costs. On the one hand, the Apollo system is well understood, and proved to be a highly successful, rugged system with a very capable launch abort system. Documentation would be very helpful in leading the designers. On the other hand, nearly every system would have to be redesigned, even if it were to be replicated. None of the existing hardware (such as CMs in Museums) was thought to be usable, because of age, obsolescence, lack of traceability, and water immersion. There would be no need for fuel cells or cryogenics, and modern guidance and communications would be lighter and less expensive.
There was not full agreement on the cost benefit of using existing Apollo documentation in the design of, what was agreed would be, a new vehicle with all new subsystems. However, it was judged that the development and manufacturing costs of an Apollo derived CRV has the potential of lower cost than a winged vehicle due to its lower complexity level.
The Operational costs would be high for a Command Module Crew Return Vehicle (CM/CRV). Because of the very low orbital delta V and the low aerodynamic cross-range, many landing sites would be required and the infrastructure for 24 hour, seven day operations would be expensive, particularly to meet the Level 1 requirement to bring the astronauts to medical care in 24 hours. By adding a Service Module, orbital delta V would make it possible to reduce dramatically the landing sites required. This is why the team surmised that a Command and Service Module Crew Return and Crew Transport Vehicle (CSM/CRV/CTV) looked attractive.
The team judged that a schedule for the CRV of 4-6 years (from contract go-ahead) and 5-7 years for the CTV or a CRV/CTV (from contract go-ahead) would be reasonable.
Although the flight hardware would be less expensive, and its impact on the Expendable Launch Vehicles would be minimal (it's just another axisymmetrical payload), the landing sites for the CRV may drive the Life Cycle costs high. By adding a Service Module (smaller than the one required to go to the moon), orbital cross-range of 3000 to 5000 ft/sec, might be gained, and the number of landing sites radically reduced. If land landings can be added to the system safely, another major reduction in life cycle costs would result, because the team believed that the system could be made re-usable.
Some Personal Thoughts
Although the team was not asked to compare the capsules to winged vehicles, and we did not, I have some comments relative to wings vs. capsules.
The Apollo Program never had a parachute failure in operation, although we had failures during the test program. We had one parachute fail due to N2O4 leaking onto the shrouds, but the vehicle landed safely on two parachutes.
The Shuttle has had a wing failure, but the failure was apparently caused by the foam insulation from the tank. Shuttle runway landings have been 100% successful.
It appears to me that the robust launch escape system of Apollo, which worked over a wide range from the launch pad to high altitude, will be hard to beat in a winged vehicle.
This Apollo based system, without aerodynamic controls, wings, and landing gear is clearly simpler.
The ablative replaceable heatshield is simpler to build and install than the corresponding winged vehicle thermal protection system. We already know the thermal distribution on the vehicle. With a land landing, a reusable heatshield might apply to the Apollo system.
A land landing is a new development for a Command Module and not an easy one. With a five-man crew, three parachutes (as proven on Apollo) or a parasail might be used (although I'm not sold on parasail reliability, and wonder how redundancy is supplied). Close to the ground, a retrorocket could be used, with a blowout hatch in the heat shield to expose the rocket. Alternately, air bags could absorb the vertical landing velocity. Any of the means of softening the land landing could be aided with crushable struts on the couches. I am not familiar with the reliability record of the Russian land landing system, although I have heard that they have had trouble with it. Tumbling while landing in a crosswind is a threat.
Landing with wings yields good atmospheric cross-range, and thus more flexibility in when and where toland. The winged system may be more Life-Cycle Cost effective because of that feature, and it might give more safety because of its ability to land at other airports.
Winged vehicles have less "g-load" (gravity load) during re-entry, relieving stress on an injured or ill crewmember.
If all things were equal, I'd choose winged vehicles. Unfortunately, they are not known to be equal, and that's why the team recommended a thorough study of the Apollo CM/SM as a CRV/CTV.
Comments on the NASA Integrated Space Transportation Program (ISTP)
The Chairman asked that I comment on some issues other than the Apollo CRV and CTV. These will be personal remarks, and not those of the Apollo CRV/CTV Team.
I support the ISTP. The OSP schedule looks reasonable, but only if funding is made available in a timely fashion. I'd like to see a strong effort in autonomous docking for either system, and in launch escape if a winged vehicle is chosen. For the Command Module CRV/CTV, development of a land landing system is the only major new technology, other than long duration storage in space. I can't really strongly recommend the land landing until a Life Cycle Cost Effectiveness study is completed. If earlier dates are strongly desired, I believe some time could be saved by accelerating Phase A and Phase B studies and initiating procurement of long lead time items just after Preliminary Design. Some increase in risk would result, but it appears that the contractors have already invested significant funds, and configurations are reasonably stabilized as compared to the Phase A and B of the Shuttle or Space Station. In the case of the Apollo combined CRV/CTV, I would consider giving the Service Module to a different contractor than the Command Module. Doing so might make it possible to do the Crew Transport Vehicle schedule in 4-6 years, and at the same time, stimulate new design at more than one contractor.
Using an Expendable Launch Vehicle for human transport is feasible, if the same attention is, or has been, given to the reliability design requirements for the ELV as NASA gives for human flight. The new Evolved Expendable Launch Vehicles (EELVs) have been designed for high reliability, and first flights look good. A robust launch escape system would reduce risk even further. A careful review of the EELVs would be needed to determine whether the NASA version would be common with the military and commercial EELV. If not, an additional expense is incurred, and less reliability advantage gained from the repeated launch of common ELVs for all launches.
The introduction of the CRV/CTV to be launched on Expendable Launch Vehicles (ELVs) will allow NASA to use the Shuttle for cargo for the ISS, to share with the OSP crew transport to the ISS, and for lower inclination orbits where heavy science payloads can be placed in orbit, maintained and upgraded, repaired, and serviced. Even if a logistics module were developed to be launched by an ELV, I firmly believe that the Shuttle will be needed until a second-generation manned launch vehicle is operational. The ISTP gives NASA more time to develop the technologies required to design a low cost to orbit launch vehicle.
A key factor that must be considered is this. Will the U.S., or the world decide to go back to the moon or Mars in the next 20 to 50 years? I'm sure space policy is dealing with that question, but assuming there is interest, we must continue low-level system studies and technology development, including nuclear rockets (unless and until something better comes along). An eventual plan to return to the moon would favor choosing a capsule approach for a CRV/CTV.
The greatest risk is doing nothing. NASA and industry management, engineers and manufacturing people are getting old, like me. A new hardware program is sorely needed to bring vibrant new people in to bear on NASA Programs. An OSP followed by a new low cost launch vehicle, followed by a phased return to the moon and Mars would be an ideal program that would bring stars to the eyes of every young American child and help rebuild American interest in engineering.
Assessment Team Members
Apollo Soyuz (ASTP) and Commander for STS-5, STS-41B, STS-35
Former Director of NASA JSC; former Manager of the Command and Service Module in the Apollo Spacecraft Program Office; former Shuttle Orbiter Project Manager, responsible for design, development, production, and flight tests; former acting Deputy Administrator.
Former V.P. and Program Manager- Apollo Command and Service Module, NAA/Rockwell; Former NASA Associate Administrator for Manned Space Flight; Former NASA Deputy Administrator
Former Director, NASA Dryden; Chief Engineer NASA F-8 DFBWwith Apollo GNC systems. Team leader.
Gemini 3, Gemini 10 (CDR), Apollo 10, Apollo 16 (CDR), STS-1 (CDR), STS9 (CDR)
The Team convened 13-14 March 2003 to conduct the assessment.
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